1. Field of the Invention
The present invention relates to an image processing apparatus and, more specifically to an image processing apparatus for forming edited images which are provided by entirely or partially transforming the original images.
2. Description of the Related Art
Recently, image forming apparatuses such as digital copying machines, facsimiles, printer apparatuses having image processing apparatuses digitally processing image signals have various image editing functions other than expansion and reduction of images and such apparatuses have superior reproductivity of gradation and colors of the images.
The image editing functions include expansion and reduction of original images as well as formation of images provided by transforming the original images into desired shapes. Images edited by such function include moved images in which the arrangement of the images are changed, mirror images in which the original images are inverted in line symmetry, inclined images in which the original images are inclined which are suitable for making design of letters, repeated images in which a part of the original image is formed repeatedly, and so on.
The moved images are formed when the image is to be formed on a sheet of paper which is larger than the sheet of paper on which the original image is formed, in order to align the center of the image with the center of the sheet of paper, for instance. The mirror images are formed when printing plates are formed, for example, the inclined images are used for lettering, and the repeated images are used when a large number of labels are to be formed.
When these edited images are to be formed, generally image data of a predetermined amount are once stored in an image memory, and the data in the image memory are rearranged based on arithmetic operations by an arithmetic unit such as a microprocessor and the like.
As disclosed in, for example, Japanese Patent Laying Open No. 59-70358, when images are to be expanded or reduced, a pair of image memory each capable of storing the prescribed amount of image data are provided. Data transfer is carried out between these two image memories, and reduced image data signals or expanded image data signals are generated by changing address designation timing between the memory storing the images to be transmitted and the memory storing the received images at the time of data transfer.
When image processing for forming edited images is carried out by utilizing a software by using a microprocessor and the like, the degree of freedom in edition can be enhanced. However, actually a prescribed processing time is required, as the speed of arithmetic processing is limited. Consequently, real time image formation cannot be carried out. When a plurality of different image editing processes are carried out by sharing one image memory in order to simplify the structure, the software becomes complicated, further reducing the speed of processing.
When expansion or reduction of an image is to be carried out on real time, image data should be taken independent from and parallel to the image processing of the prescribed amount of image data, so that at least two image memories are needed. Therefore, when expansion or reduction of an image is to be carried out by data transfer between a pair of image memories as in the conventional image processing apparatus, four image memories in total are necessary, which increases the size of the image processing apparatus.